From c4baf876d4896318817dbcc7d5b03680c8142bc9 Mon Sep 17 00:00:00 2001
From: Antonin Portelli <antonin.portelli@me.com>
Date: Fri, 2 Mar 2018 18:40:18 +0000
Subject: [PATCH] Hadrons: graph consistency check

---
 extras/Hadrons/VirtualMachine.cc | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/extras/Hadrons/VirtualMachine.cc b/extras/Hadrons/VirtualMachine.cc
index c91667e7..1bd18100 100644
--- a/extras/Hadrons/VirtualMachine.cc
+++ b/extras/Hadrons/VirtualMachine.cc
@@ -296,7 +296,18 @@ void VirtualMachine::makeModuleGraph(void)
     {
         for (auto &in: module_[m].input)
         {
-            graph.addEdge(env().getObjectModule(in), m);
+            int min = env().getObjectModule(in);
+
+            if (min < 0)
+            {
+                HADRON_ERROR(Definition, "object with address " 
+                             + std::to_string(in) 
+                             + " is not produced by any module");
+            }
+            else
+            {
+                graph.addEdge(min, m);
+            }
         }
     }
     graph_ = graph;